• Journal of Medicine and Life Science
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• v.17 no.3
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• pp.65-73
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• 2020

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a single-gene disease of the cerebral small blood vessels caused by mutations in the NOTCH3 gene on chromosome 19. Although CADASIL was known as a rare disease, recent research has suggested that the NOTCH variants could be found frequently even in the general population. The main clinical features included recurrent stroke, migraine, psychiatric symptoms, and progressive cognitive decline. On brain magnetic resonance imaging, patients with CADASIL showed multifocal white matter hyperintensity lesions, lacunar infarcts, microbleeds, and brain atrophy. Among them, lacunar infarcts and brain atrophy are important in predicting the clinical outcomes of patients with CADASIL. In the Jeju National University Hospital, we have diagnosed 213 CADASIL patients from 2004 to 2020. Most NOTCH3 mutations were located in exon 11 (94.4%), and p.Arg544Cys was the most common mutation. The mean age at diagnosis was 61.0±12.8 years. The most common presenting symptoms were ischemic stroke (24.4%), followed by cognitive impairment(15.0%), headache (8.9%), and dizziness(8.0%). Although the exact prevalence of CADASIL in Jeju is still unknown, the disease prevalence could be as high as 1% of the population considering the prevalence reported in Taiwan. Therefore, it is necessary to discover efficient biomarkers and genetic tests that can accurately screen and diagnose patients suspected of having CADASIL in this region. Ultimately, it is urgent to explore the exact pathogenesis of the disease to identify leading substances of treatment potential, and for this, multi-disciplinary research through active support from the Jeju provincial government as well as the national government is essential.

• Journal of Genetic Medicine
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• v.18 no.1
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• pp.64-69
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• 2021

Primary cilium has a signal transduction function that is essential for brain development, and also determines cell polarity and acts as a mediator for important signaling systems, especially the Sonic Hedgehog (SHH) pathway. TBC1D32 is a ciliary protein, implicated in SHH signaling. Biallelic mutations in the TBC1D32 gene causes a kind of ciliopathy, heterogeneous developmental or degenerative disorders that affect multiple organs, including the brain. Here we report a boy who carried compound heterozygous variants in TBC1D32. The patient showed hypotonia, respiratory difficulty, and multiple anomalies at his birth. He was diagnosed with congenital hypopituitarism and treated with T4, hydrocortisone, and growth hormone. Despite the hormonal replacement, the patient needed long-term respiratory support with tracheostomy and nutritional support with a feeding tube. His developmental milestones were severely retarded. Hydrocephalus and strabismus developed and both required surgery, during the outpatient follow-up. Whole-exome sequencing indicated compound heterozygous variants, c.2200C>T (p.Arg734^*) and c.156-1G>T, in TBC1D32 gene. This is the first Korean case of TBC1D32-related ciliopathy and we reported detailed and sequential clinical features. This case demonstrated the utility of whole-exome sequencing and provided valuable clinical data on ultra-rare disease.

• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.506-518
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• 2021

The imprinted tumour suppressor NOEY2 is downregulated in various cancer types, including ovarian cancers. Recent data suggest that NOEY2 plays an essential role in regulating the cell cycle, angiogenesis and autophagy in tumorigenesis. However, its detailed molecular function and mechanisms in ovarian tumours remain unclear. In this report, we initially demonstrated the inhibitory effect of NOEY2 on tumour growth by utilising a xenograft tumour model. NOEY2 attenuated the cell growth approximately fourfold and significantly reduced tumour vascularity. NOEY2 inhibited the phosphorylation of the signalling components downstream of phosphatidylinositol-3'-kinase (PI3K), including phosphoinositide-dependent protein kinase 1 (PDK-1), tuberous sclerosis complex 2 (TSC-2) and p70 ribosomal protein S6 kinase (p70S6K), during ovarian tumour progression via direct binding to vascular endothelial growth factor receptor-2 (VEGFR-2). Particularly, the N-terminal domain of NOEY2 (NOEY2-N) had a potent anti-angiogenic activity and dramatically downregulated VEGF and hypoxia-inducible factor-1α (HIF-1α), key regulators of angiogenesis. Since no X-ray or nuclear magnetic resonance structures is available for NOEY2, we constructed the three-dimensional structure of this protein via molecular modelling methods, such as homology modelling and molecular dynamic simulations. Thereby, Lys15 and Arg16 appeared as key residues in the N-terminal domain. We also found that NOEY2-N acts as a potent inhibitor of tumorigenesis and angiogenesis. These findings provide convincing evidence that NOEY2-N regulates endothelial cell function and angiogenesis by interrupting the VEGFR-2/PDK-1/GSK-3β signal transduction and thus strongly suggest that NOEY2-N might serve as a novel anti-tumour and anti-angiogenic agent against many diseases, including ovarian cancer.

• Molecules and Cells
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• v.45 no.6
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• pp.425-434
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• 2022

The post-translational modification (e.g., phosphorylation) of estrogen receptor α (ERα) plays a role in controlling the expression and subcellular localization of ERα as well as its sensitivity to hormone response. Here, we show that ERα is also modified by UFM1 and this modification (ufmylation) plays a crucial role in promoting the stability and transactivity of ERα, which in turn promotes breast cancer development. The elevation of ufmylation via the knockdown of UFSP2 (the UFM1-deconjugating enzyme in humans) dramatically increases ERα stability by inhibiting ubiquitination. In contrast, ERα stability is decreased by the prevention of ufmylation via the silencing of UBA5 (the UFM1-activating E1 enzyme). Lys171 and Lys180 of ERα were identified as the major UFM1 acceptor sites, and the replacement of both Lys residues by Arg (2KR mutation) markedly reduced ERα stability. Moreover, the 2KR mutation abrogated the 17β-estradiol-induced transactivity of ERα and the expression of its downstream target genes, including pS2, cyclin D1, and c-Myc; this indicates that ERα ufmylation is required for its transactivation function. In addition, the 2KR mutation prevented anchorage-independent colony formation by MCF7 cells. Most notably, the expression of UFM1 and its conjugating machinery (i.e., UBA5, UFC1, UFL1, and UFBP1) were dramatically upregulated in ERα-positive breast cancer cell lines and tissues. Collectively, these findings implicate a critical role attributed to ERα ufmylation in breast cancer development by ameliorating its stability and transactivity.

• Journal of Genetic Medicine
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• v.19 no.2
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• pp.94-99
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• 2022

Lesch-Nyhan disease (LND) is a rare X-linked recessive inherited purine metabolic disorder that accompanies neurodevelopmental problems. Neurofibromatosis type 1 (NF1) is a relatively common autosomal dominant inherited genetic disorder characterized by tumors in various systems. Some children with NF1 also accompanies neurodevelopmental problems. Here, we describe a 5-year-old boy with a maternally inherited pathogenic variant in NF1 and hypoxanthine-guanine phosphoribosyltransferase (HPRT). He was referred for severe neurodevelopmental impairment and hyperuricemia. His mother was diagnosed with NF1 and the patient was also suspected of having NF1 because of cafe au lait macules. He had dystonia, rigidity, cognitive deficit, and speech/language impairment. Serum and urine uric acid concentrations were elevated. He had more severe neurodevelopmental delay than patients with only NF1, so his clinical symptoms could not be fully understood by the disease alone. To find the cause of his neurologic symptoms and hyperuricemia, the patient and his mother underwent a whole-exome sequencing test. As a result, the pathogenic variant c.151C>T (p.Arg51Ter) in HPRT1 was identified as hemizygote in the patient and heterozygote in his mother. The pathogenic variant c.7682C>G (p.Ser2561Ter) in NF-1 was identified as heterozygotes in both of them. Although the clinical symptoms of both diseases were overlapping and complicated, genetic testing was helpful for accurate diagnosis and treatment. Therefore, we suggest to consider preemptive genetic evaluation if there are symptoms not sufficiently explained by known existing diseases. And it is considered valuable to review this rare case to understand the clinical course and possible synergic effects of these diseases.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.200-209
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• 2023

Patients with non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) amplification or sensitive mutations initially respond to the tyrosine kinase inhibitor gefitinib, however, the treatment becomes less effective over time by resistance mechanism including mesenchymal-epithelial transition (MET) overexpression. A therapeutic strategy targeting MET and EGFR may be a means to overcoming resistance to gefitinib. In the present study, we found that picropodophyllotoxin (PPT), derived from the roots of Podophyllum hexandrum, inhibited both EGFR and MET in NSCLC cells. The antitumor efficacy of PPT in gefitinib-resistant NSCLC cells (HCC827GR), was confirmed by suppression of cell proliferation and anchorage-independent colony growth. In the targeting of EGFR and MET, PPT bound with EGFR and MET, ex vivo, and blocked both kinases activity. The binding sites between PPT and EGFR or MET in the computational docking model were predicted at Gly772/Met769 and Arg1086/Tyr1230 of each ATP-binding pocket, respectively. PPT treatment of HCC827GR cells increased the number of annexin V-positive and subG1 cells. PPT also caused G2/M cell-cycle arrest together with related protein regulation. The inhibition of EGFR and MET by PPT treatment led to decreases in the phosphorylation of the downstream-proteins, AKT and ERK. In addition, PPT induced reactive oxygen species (ROS) production and GRP78, CHOP, DR5, and DR4 expression, mitochondrial dysfunction, and regulated involving signal-proteins. Taken together, PPT alleviated gefitinib-resistant NSCLC cell growth and induced apoptosis by reducing EGFR and MET activity. Therefore, our results suggest that PPT can be a promising therapeutic agent for gefitinib-resistant NSCLC.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.2
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• pp.92-101
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• 2020

The cyclic Arg-Gly-Asp (cRGD) peptide is well-known as a binding molecule to the integrin α_vβ₃ receptor which is highly expressed on activated endothelial cells and new blood vessels in tumors. Although numerous results have been reported by the usage of cRGD peptide-based ligands for cancer diagnosis and therapy, the distinct mechanisms, and functions of cRGD-integrin binding to cancer cells are still being investigated. In this study, we evaluated the internalization efficacy of different types of cRGD peptides (monomer, dimer and tetramer form) in integrin α_vβ₃ overexpressing cancer cells. Western blot and flow cytometric analysis showed U87MG expresses highly integrin α_vβ₃, whereas CT-26 does not show integrin α_vβ₃ expression. Cytotoxicity assay indicated that all cRGD peptides (0-200 µM) had at least 70-80% of viability in U87MG cells. Fluorescence images showed cRGD dimer peptides have the highest cellular internalization compare to cRGD monomer and cRGD tetramer peptides. Additionally, transmission electron microscope results clearly visualized the endocytic internalization of integrin α_vβ₃ receptors and correlated with confocal microscopic results. These results support the rationale for the use of cRGD dimer peptides for imaging, diagnosis, or therapy of integrin α_vβ₃-rich glioblastoma.

• Journal of Microbiology and Biotechnology
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• v.33 no.3
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• pp.387-397
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• 2023

Cytochrome P450 (CYP) is a heme-containing enzyme that catalyzes hydroxylation reactions with various substrate molecules. Steroid hydroxylases are particularly useful for effectively introducing hydroxyl groups into a wide range of steroids in the pharmaceutical industry. This study reports a newly identified CYP steroid hydroxylase (BaCYP106A6) from the bacterium Bacillus sp. and characterizes it using an in vitro enzyme assay and structural investigation. Bioconversion assays indicated that BaCYP106A1 catalyzes the hydroxylation of progesterone and androstenedione, whereas no or low conversion was observed with 11β-hydroxysteroids such as cortisol, corticosterone, dexamethasone, and prednisolone. In addition, the crystal structure of BaCYP106A6 was determined at a resolution of 2.8 Å to investigate the configuration of the substrate-binding site and understand substrate preference. This structural characterization and comparison with other bacterial steroid hydroxylase CYPs allowed us to identify a unique Arg295 residue that may serve as the key residue for substrate specificity and regioselectivity in BaCYP106A6. This observation provides valuable background for further protein engineering to design commercially useful CYP steroid hydroxylases with different substrate specificities.

• Journal of the Korean Wood Science and Technology
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• v.51 no.3
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• pp.183-196
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• 2023

Recently, the morphological and molecular features of five stain fungi infecting rubberwood (Hevea brasiliensis), namely Paecilomyces maximus, Paecilomyces formosus, Penicillium crustosum, Paecilomyces lecythidis and Aspergillus chevalieri, have been studied. Prior to this study, the authors revealed that catechin from gambir (Uncaria gambir) could inhibit the growth of the white-rot fungus Schizophyllum commune, and it was important to determine the bioactivity of the aforementioned agent against A. chevalieri. The efficacy of the biocidal agent was examined using a laboratory wooden block test. Rubberwood blocks, 8 mm in thickness, 20 mm in width, and 30 mm in length, were impregnated with catechin solution at concentrations of 6%, 9%, 12%, and 15% (w/v) using the vacuum-pressure method, and their bioactivity was monitored over three weeks through visual and scanning electron microscope assessment of fungal growth as well as the discoloration intensity of the wood samples. The results showed that catechin treatment increased the resistance of wood samples to A. chevalieri. Overall, the higher the catechin concentration, the lower the fungal growth. The lowest fungal growth was observed in the wood samples treated with 12% and 15% catechin (score of 0), demonstrating no discoloration. In contrast, the fungal growth score of the untreated wood samples reached 4, indicating severe discoloration. Catechins appear to be adequate biofungicides against stain fungi in rubberwood.

• Journal of Genetic Medicine
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• v.21 no.1
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• pp.31-35
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• 2024

Allan-Herndon-Dudley syndrome (AHDS) is a rare X-linked neurodevelopmental disorder with abnormal thyroid function caused by mutation in the solute carrier family 16 member 2 (SLC16A2) gene. Clinical manifestations of AHDS are global or axial hypotonia, a variety of movement disorders, severe intellectual disability, quadriplegia or spastic diplegia, growth failure, and seizures. A 10-year-old boy visited our hospital with the chief complaint of newly onset generalized tonic seizures with vocalization of weekly to daily frequency. He showed early infantile hypotonia, severe intellectual disability, and frequent respiratory infections. He could not walk independently and was non-verbal. Electroencephalogram revealed generalized slow spike and waves with multifocal spikes and slow background rhythms. His tonic seizures were controlled with more than two anti-seizure medications (ASMs). At 11 years of age, he was evaluated for thyroid function as part of regular screening for ASM maintenance and was found to have abnormal thyroid function. We performed whole exome sequencing for severe global developmental delay, drug-resistant epilepsy, and abnormal thyroid function. The hemizygous c.940C>T (p.Arg314Ter) variant in the SLC16A2 gene (NM_006517.5) was identified and confirmed based on Sanger sequencing. Herein, we describe a case of an AHDS patient with late-onset drug-resistant epilepsy combined with congenital hypotonia, global developmental delay, and abnormal thyroid function results. To the best of our knowledge, this is the oldest adolescent among AHDS cases reported in Korea. In this report, clinical characteristics of a mid-adolescence patient with AHDS were presented.